John K. Starley in 1885 produced a bicycle named “rover” that featured a steerable front wheel and a chain drive to a rear wheel. The chain drive improved comfort and speed and allowed for a smooth, relaxed and injury free foot pedaling of the bicycle. In the late 1960 Americans, recognizing the value of exercise and energy efficient transportation predicated a bike boom for ten-speed bicycles. Conventional bicycles have seats that irritate human body posteriors and are limited to outdoor use. In northern climates bicycles are not used due to snow and ice road conditions. Indoor exercise machines, including stationary bikes, are non-moving machines that lack outside visual stimuli during use which may cause boredom for the user. Numerous bicycle improvements and modifications have been made to improve bicycle performance, exercise, and safety. One of these bicycles is known as a stepper bike. The stepper bike allows users to use their upper body and lower body to power the vehicle while riding. The stepper bike has no seat on it's frame. Movable foot pedals are depressed by the user's feet to propel the bike. The user positions him or herself by holding onto handlebars and standing on the foot pedals. Then the user shifts his or her weight alternately from foot to foot, and thereby moves the foot pedals up and down in a walking motion to transport torque to the bikes drive wheel. Examples of stepper bikes are shown and described in the following U.S. patents.
M. T. Ludwigson and H. E. Ludwigson in U.S. Pat. No. 2,707,112 discloses a pedal operated scooter having a frame supported on a surface with a front steering wheel and rim drive wheels. A pair of foot pedals operate a crank mechanism to turn a shaft, a unidirectional driving mechanism, and an endless belt transmits power from the shaft to a rear wheel drive shaft connected to the rear wheels.
N. J. Rills in U.S. Pat. No. 4,411,442 discloses a foot operated vehicle having a platform connected to support members accommodating front and rear wheels. Independently depressable front and rear pedals are operable to transmit power to the front and rear wheels. Springs associated with each pedal bias the pedals toward upper positions.
P. A. Berman et al in U.S. Pat. No. 5,368,321 discloses a four wheel vehicle propelled by vertical foot movement of a human rider. A pair of footboards located on opposite sites of a shroud connected to pivot members are coupled to a drive mechanism for the rear wheels. The rider alternatively presses the footboards downward to apply driving torque to the drive mechanism to turn the rear wheels.
S. B. M. Bhoopathy in U.S. Pat. No. 6,716,141 discloses a foot pedal scooter having a frame connected to a front steering wheel and a rear drive wheel. A pair of foot pedals pivotally mounted on the frame angularly move arms connected to chains trained over sprockets. Free wheel elements drivably connected to the sprockets transmit power to the drive wheels. Springs connected to the chains bias the foot pedals to up positions.